How JustAnswer Works:

  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.

Ask Robert Your Own Question

Robert, UK Qualified Car Technician
Category: Car
Satisfied Customers: 4532
Experience:  Fully qualified / self employed garage technician in the UK
Type Your Car Question Here...
Robert is online now

My citroen relay leaks a lot of water on a journey, it is

Customer Question

my citroen relay leaks a lot of water on a journey, it is not going into the oil, nor out of the exhaust. we have just had a reconditioned engine put in. It does not leak when stood.
Submitted: 11 months ago.
Category: Car
Expert:  Robert replied 11 months ago.


In what way have you checked for leaks?

How quickly does it loose coolant etc? and or how much needs to be topped up?

Customer: replied 11 months ago.
We have looked all around and underneath vehicle, we have had it pressure tested. It does not loose water when stood and not running. It looses the header tank in a 160 mile journey. We wonder if it could be the fans by radiator, or the radiator cap. It does not over heat. The red light comes on when it is short of water.
Customer: replied 11 months ago.
It seems like it is using water to cool, but we are no mechanics
Customer: replied 11 months ago.
Would it be an electrical fault
Expert:  Robert replied 11 months ago.

If its been pressure need to let it sit under pressure for at least 15minutes..if it holds..then the coolant system doesnt have a the pressure test should help ID leaks that can occur if the engine is hot when things expand..but if nothing is seen or the pressure guage doesnt move after 15minutes..then the system is fine...that would leave maybe possible bad expansion tank cap maybe allowing the coolant to boil and you may want replace that and see if that helps....Normally during a engine swap you will need to reconnect coolant pipes thats why is best to recheck those are tight..aswell as the radiator too..but if all these are dry and tight then you can sort of focus i say with the cap as above... The fans or an electrical fault shouldnt coolant loss...

Customer: replied 11 months ago.
Everything is dry, so will get An expansion cap, and try, will let u know outcome
Expert:  Robert replied 11 months ago. problem...In the mean time if you could leave a rating for me before you log out..much appreciated

Customer: replied 11 months ago.
Will wait to see if cap sorts problem, we have come on a journey, after 70 miles red light came on,we put 2and a half litres of water in
Expert:  Robert replied 11 months ago.

Unless the cap is faulty - i cant see how it could loose that amount of coolant but not show any signs of overheating or even a sign of leak somewhere..if the pressure test was done correctly - that will only leave either the system maybe over pressurizing exhaust gas leaking into the system thus forcing the coolant out..a block test would check for that...

Customer: replied 11 months ago.
Could you please explain how a block test is carried out. Just rechecked under vehicle and around expansion tank, no signs of any leaks.
Expert:  Robert replied 11 months ago.

You need a block test kit - it test for combustion leak and can verfiy that the coolant system maybe overpressurising.. in the kit you have tube and suction bulb on the fill the tube with the special it onto the neck of the expansion tank..and squeeze the bulb a few times..then start the engine up..whilst its running watch to see if the dye changes colour to Yellow then you have internal leak..if its stays Blue then you have no leak...Having said that any good garage should have this it maybe worth enquiring locally to have it done than buy the kit yourself.....if its still Loosing coolant then the cap might be your could also be worth making sure the Oil is ok and water not getting into that instead...have you checked the heater matrix and around the floor area just to be sure it not leaking into the cabin

Customer: replied 11 months ago.
Thank you, ***** ***** try cap first
Expert:  Robert replied 11 months ago.

no probs

What Customers are Saying:

  • 9 dollars, 2 hours of my time, and I drove away. Your diagnosis was right on the mark. Thank you so much. Phil
< Previous | Next >
  • 9 dollars, 2 hours of my time, and I drove away. Your diagnosis was right on the mark. Thank you so much. Phil
  • Lurch. Thank you very much. I had real doubts about this website but your promptness of response, quick followup and to the point answer with picture was incredible. Charles
  • As a single woman, I really appreciate an excellent and affordable opinion.
    Thank you Geordie, I will not hesitate to contact justanswer in the future!
  • Another great insight to what may be the problem. I will have my mechanic take a look at it tomorrow. Thanks again, do indeed know your stuff. Jim
  • I would (and have) recommend your site to others I was quite satisfied with the quality of the information received, the professional with whom I interacted, and the quick response time. Thanks, and be sure that I'll be back whenever I need a question answered in a hurry. Stephanie P
  • Wonderful service, prompt, efficient, and accurate. Couldn't have asked for more. I cannot thank you enough for your help. Mary C.
  • This expert is wonderful. They truly know what they are talking about, and they actually care about you. They really helped put my nerves at ease. Thank you so much!!!! Alex

Meet The Experts:

  • Greg



    Satisfied Customers:

    Automotive diagnostic tech
< Previous | Next >
  • Greg's Avatar



    Satisfied Customers:

    Automotive diagnostic tech
  • Matt's Avatar


    Mechanical Engineer

    Satisfied Customers:

    BEng hons Mech engineering, in auto industry 22 years
  • Ross's Avatar


    Diagnostic and repair technician

    Satisfied Customers:

    Licensed diagnostic and repair technician
  • Rob's Avatar


    ASE Certified Technician

    Satisfied Customers:

    30 years trade experience
  • uk_iaibal's Avatar


    UK Car Mechanic

    Satisfied Customers:

    Verified Car Mechanic.
  • Billy's Avatar


    Trainer/ Master Technician

    Satisfied Customers:

    Trainer 8+ years, master tech. 10+ years, SAE member
  • Mike Kelly's Avatar

    Mike Kelly

    Auto Service Technician

    Satisfied Customers:

    17 years experience as an auto mechanic, foreign and domestic. 5 years running my own repair business.